Often, the solution is administered in what is called a drip, which means the medicine of any sort drips into the IV site at planned intervals, through a tube. In many cases people have a continuous drip, where medication or fluids go in at regular times until the bag of medicine or fluids is empty.
As you can see, muscle contraction is regulated by the level of calcium ions in the cytoplasm. In skeletal muscle, calcium ions work at the level of actin (actin-regulated contraction). They move the troponin-tropomyosin complex off the binding sites, allowing actin and myosin to interact.
In response to a stimulus, the brain or the spinal cord may initiate muscle cell contraction to enable movement. The neurotransmitter that signals muscle cell contraction is acetylcholine, and it is released in the synapse between the neuron and the muscle cell. If the acetylcholine that is released is not broken down, the muscle cells remain in a contracted state and cannot respond effectively to new signals from the brain.